Medical devices are often used as diagnostic devices and/or therapeutic devices in diagnosing and/or treating medical conditions of patients. For example, a blood glucose meter is used as a diagnostic device to measure blood glucose levels of patients suffering from diabetes. An insulin infusion pump is used as a therapeutic device to administer insulin to patients suffering from diabetes.
Diabetes mellitus, often referred to as diabetes, is a chronic condition in which a person has elevated blood glucose levels that result from defects in the body's ability to produce and/or use insulin. There are three main types of diabetes. Type 1 diabetes may be autoimmune, genetic, and/or environmental and usually strikes children and young adults. Type 2 diabetes accounts for 90-95% of diabetes cases and is linked to obesity and physical inactivity. Gestational diabetes is a form of glucose intolerance diagnosed during pregnancy and usually resolves spontaneously after delivery.
In 2009, according to the World Health Organization, at least 220 million people worldwide suffer from diabetes. In 2005, an estimated 1.1 million people died from diabetes. The incidence of diabetes is increasing rapidly, and it is estimated that between 2005 and 2030, the number of deaths from diabetes will double. In the United States, nearly 24 million Americans have diabetes, and an estimated 25% of seniors age 60 and older are affected. The Centers for Disease Control and Prevention forecast that 1 in 3 Americans born after 2000 will develop diabetes during their lifetime. The National Diabetes Information Clearinghouse estimates that diabetes costs $132 billion in the United States alone every year. Without treatment, diabetes can lead to severe complications such as heart disease, stroke, blindness, kidney failure, amputations, and death related to pneumonia and flu.
Diabetes is managed primarily by controlling the level of glucose in the bloodstream. This level complex as the level of blood glucose entering the bloodstream is dynamic and complex, and is affected by multiple factors including the amount and type of food consumed, and the amount of insulin (which mediates transport of glucose across cell membranes) in the blood. Variation of insulin in the bloodstream that controls the transport of glucose out of the bloodstream also complicates diabetes management. Blood glucose levels are also sensitive to diet and exercise, but also can be affected by sleep, stress, smoking, travel, illness, menses, and other psychological and lifestyle factors unique to individual patients. The dynamic nature of blood glucose and insulin and all other factors affecting blood glucose often require a person with diabetes to forecast blood glucose levels. Therefore, therapy in the form of insulin, oral medications, or both can be timed to maintain blood glucose levels in an appropriate range.
Management of diabetes is time-consuming for because of the need to consistently obtain reliable diagnostic information, follow prescribed therapy, and manage lifestyle on a daily basis. Diagnostic information such as blood glucose is typically obtained from a capillary blood sample with a lancing device and is then measured with a handheld blood glucose meter. Interstitial glucose levels may be obtained from a continuous glucose sensor worn on the body. Prescribed therapies may include insulin, oral medications, or both. Insulin can be delivered with a syringe, an ambulatory infusion pump, or a combination of both. With insulin therapy, determining the amount of insulin to be injected can require forecasting meal composition of fat, carbohydrates, and proteins along with effects of exercise or other physiological states. The management of lifestyle factors such as body weight, diet, and exercise can significantly influence the type and effectiveness of therapy.
Management of diabetes involves large amounts of diagnostic data and prescriptive data acquired in a variety of ways: from medical devices, from personal healthcare devices, from patient-recorded logs, from laboratory tests, and from healthcare professional recommendations. Medical devices include self-monitoring blood glucose (bG) meters (BGMs), continuous glucose monitors (CGMs), ambulatory insulin infusion pumps, diabetes analysis software, and diabetes device configuration software, each of which generates and/or manages large amounts of diagnostic and prescriptive data. Personal healthcare devices include weight scales, blood pressure cuffs, exercise machines, thermometers, and weight management software. Patient recorded logs include information relating to meals, exercise, and lifestyle. Laboratory test results include HbAlC, cholesterol, triglycerides, and glucose tolerance. Healthcare professional recommendations include prescriptions, diets, test plans, and other information relating to the treatment of the patient.
There is a need for a handheld device to aggregate, manipulate, manage, present, and communicate diagnostic data and prescriptive data from medical devices, personal healthcare devices, patient recorded information, biomarker information, and recorded information in an efficient manner. The handheld device can improve the care and health of a person with diabetes so that the person with diabetes can lead a full life and reduce the risk of complications from diabetes.
Additionally, since the handheld device is battery powered, there is a need to effectively manage power consumption of the handheld device to optimize operating times between battery recharges. Specifically, there is a need to control the power consumption by selectively disabling one or more components of the handheld device based on the usage and internal temperature of the handheld device. Further, the handheld device measures blood glucose levels by performing chemical analysis of samples deposited on a strip, which is inserted into a port of the handheld device. Since chemical processes used in the chemical analysis are sensitive to temperature, there is a need to monitor internal temperature of the handheld device, estimate an ambient temperature proximate to a reaction site on the strip based on the internal temperature, and selectively disable one or more components of the handheld device based on the ambient temperature.
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.